AKD4388-SB Datasheet, PDF (6/26 Pages) Asahi Kasei Microsystems – 192kHz sampling 24Bit ΔΣ DAC

ASAHI KASEI
[AKD4388-SB]
 External Analog Circuit
The 2nd order LPF (fc=125.6kHz, Q=0.753) which adds differential outputs of the AK4388 is implemented on the board. When the further
attenuation of the out-band noise is needed, some additional LPF is required. Analog signal is output through BNC connectors on the board.
And the output level of the AK4388 is 5.67Vpp@5V.
C1
R4
R3
R0
22u
R1
AOUT
22K
+Vop
R2
C2
-Vop
Analog
Out
fc=125.6kHz, Q=0.753, g=0.060dB at 40kHz
Figure 4. External Analog Filter
R₀
R₁
R₂
R₃
R₄
C₁
C₂
910
1.8k
3.9k
3.3k
3.9k
390p
390p
Table 8. The value of R,C on this board
fin
20kHz
40kHz
Frequency Response 0.023dB 0.060dB
Table 9. Frequency Response of LPF
80kHz
-0.288dB
<Calculation>
Amplitude = 20 log
K
[dB],
[1-(f/fc)²] ²+[(1/Q)(f/fc)] ²
K=
R₃+R₄
R₄
,
fc=
ω₀
2π
,
ω₀=
1
,
C₁C₂R₁R₂
Q = 2πfc
1
+
1
1
+ ^1−k
C₁R₁ C₁R₂ C₂ R₂
<KM083502>
6
2006/09